Three-dimensional circular spiral photonic crystal structures recorded by femtosecond pulses

Photonic crystal structures having three-dimensional (3D) circular spiral architecture have large theoretical photonic band-gap but cannot be implemented by most of the existing microfabrication techniques. We have successfully used a highly versatile 3D microstructuring technique called femtosecond laser microfabrication to prepare templates of the circular spiral photonic crystals in a commercially available photoresist SU-8. The structures fabricated have good structural quality, are highly periodic and exhibit spectral signatures of photonic bands dispersion in the short infrared wavelength region. (c) 2006 Elsevier B.V. All rights reserved.